A metrological atomic force microscope
Name
51927798-MIT.pdf
Description
Full printable version
Size
12.61 MB
Format
Adobe PDF
Checksum (MD5)
59f878d2f9289e1d68436b3fb3e64f3b
Author(s)
Stein, Andrew John, 1978-
Advisor(s)
David L. Trumper.
Date Issued
2002
Publisher
Massachusetts Institute of Technology
Abstract
This thesis describes the design, fabrication, and testing of a metrological atomic force microscope (AFM). This design serves as a prototype for a similar system that will later be integrated with the Sub-Atomic Measuring Machine (SAMM) under development in collaboration with the University of North Carolina at Charlotte. The microscope uses a piezoelectric tube scanner with a quartz tuning fork proximity sensor to image three-dimensional sample topographies. The probe position is measured with a set of capacitance sensors, aligned so as to minimize Abbe offset error, for direct measurement of probe tip displacements. A PC-based digital control system provides closed-loop control of the lateral scanning and axial height regulation actions of the probe assembly. The lateral scanning system, which dictates the probe's motion in directions parallel to the sample plane, has measured -3 dB closed-loop bandwidths of 189 Hz and 191 Hz in the X and Y directions, respectively. Meanwhile, the axial height regulator, which adjusts the length of the tube scanner to control for a constant gap between the probe tip and the sample surface, has demonstrated a -3 dB closed-loop bandwidth of as high as 184 Hz. The metrological AFM is operational and has been used to collect several images of sample surfaces. Images taken of a silicon calibration grating indicate that the microscope can easily resolve 100 nm-scale step changes in height. However, several errors are observed in the image data. Possible reasons for these errors are discussed, and ideas for follow-on work are suggested.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.
Includes bibliographical references (p. 245-248).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Subjects
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
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